Embodiments of the inventive subject matter generally relate to the field of communication devices and, more particularly, to tri-state control for a line driver.
Communication devices comprise a transmitter and a receiver that typically share a common communication medium for transmitting or receiving signals. For a wired communication network, the output impedance of the transmitter should be low in order to drive the low impedance communication medium. A low impedance at the output of the transmitter (e.g., at a line driver circuit) can enable a signal that is to be transmitted to be properly coupled to the communication medium. However, when the receiver is receiving a signal via the communication medium, the output impedance of the transmitter should be high to ensure that the received signal is coupled to the receiver and not to the transmitter.